Sheet-glass-edge-forming means



Sept. 18, 1928. 1,684,440

F. FRAsER SHEET GLASS EDGE FORMING MEANS Original Filed June 5, 1925INVENT UIQ Patented Sept. 18, 1928.

UNITED STATES PATENT OFFICE.

FRANK FRASER, OF TOLEDO, OHIO, ASSIGNOR TO THE LIBBEY-OWENS SEEET GLASSCOMPANY, OF TOLEDO, OHIO, A CORPOBATION OF OHIO.

SHEET-GLASS-EDGE-FOBMIN G MEANS.

Application filed June 5, 1925, Serial No. 35,082. Benewed September 26,1927.

The present invention relates to sheet glass apparatus, and hasparticular reference to sheet edge forming means.

An important object of the invention s to rovide sheet glass apparatusfor producng Eat sheet glass, and includes means arranged at both edgesof the sheet adapted to engage and form a suitable edge on the sheetcapable of over-coming the natural tendency of the sheet to narrow.

Another object of the inventions to prcvide stationary edge means forgrppug the edges of the sheet at their bases and movable means above thestationary means to further assist in maintaining the sheet to width.

Still another object of the invention s to provide at each edge of thesheet being drawn from a mass of molten glass a statonary block memberhaving a slot therein through which the edge of the sheet is drawn androtatable rolls above the slot for assistng the block means in creatingan edge on the sheet, the said rolls being adapted to either retard oradvanee the edge glass.

Other objects and advantages of the invention will become apparentduring the course of the following description.

In the drawings wherein like numerals are employed to designate likeparts throughout the same,

Fig. 1 is a fragmentary transverse vertcal section through a sheet glassapparatusllustrating my improved device in operation,

Fig. 2 is an end view thereof,

Fig. 3 is a top plan, and

Fig. 4 is a perspective view.

This device is particularly well-adapted for use in the Colburn type ofmachine as set forth in Patent No. 1248809, granted December 4, 1917,although it is not necessarily limited to the Colburn machine as it canbe used in any type of machine wherein a flat sheet of glass is drawnfrom a source of molten glass. 4

The numeral 5 designates a so-called drawing pot containing a mass ofmolten glass 6, from which a sheet 7 is drawn from the sheet source 8. Abending member 9 may be provided to deflect the sheet from one plane toanother.

In the Colburn machine a pair of rotatable knurled rolls are positionedat both edges of the sheet being drawn at the meniscus thereof to form aso-called knu'led edge on the sheet to hold the same to width. Thenatural tendency of a sheet of glass being drawn from a mass is tonarrow at its base and draw to a thread. One of the great difficultiesin the production of sheet glass is to prevent this natural tendency ofthe glass to narrow without spoiling the quality of sheet formed.

Although the knurled rolls used in the Colburn process are entirelysatisfactory, they form what is known as a knurled edge on the sheet anda thickened portion which extends about six or severi inches from theedges toward the center, which edges must be removed when the sheet isbeing cut up into commercial sizes. The net width of sheet is thereforeconsiderably less than the gross width.

It is an aim of the present invention to provide means capable ofholding the sheet to width, at least as satisfactorily as the knurledrolls now used, and which will also hold the sheet to width withoutcreating such a large useless portion.

The numeral 10 designates what may be called a slotted block. The slotis indicated as at 11. The block may be fornd from a refractory materialsuch as clay, or as shown in the drawings may be forned from aprefe-ably non-Corrosive metal which may be internally cooled as throughthe conduits 12. Thus the blocks may be formed with an internal borehaving connection with the conduits 12, whereby a cooling medium such asair or water may be continuously ci'cnlated through the said block. Theblock may assume any number of shapes, and as shown in F ig. 2 comprisea pair of foot portions 13 which are adapted to be partially submergedin the bath of molten glass from which the sheet is drawn. As shown inFig. 4 the slot is eontinued up the sheet for a comparatively highdistance by making the neck 14 comparativelv taller than the neck 15 inFig. 2. The bloeks may be carried on the arms 16 which are supported inany suitable manner. The slotted members have a duel function in thatthey create a positive frictional resistdnce to the glass passing intothe bordet' portions of the sheet and they also absorb sufficient heatfrom this glass to create a relatively viscous edge capahle ofovercoming the natural tendency of the sheet to narrow. The

glass will drag along the bottom of the shoes 13 because of the naturaltendency of molten glass to adhere to such bodies.

The slot 11 may be enlarged at its end as at 17 to form what is known asa headed edge 18.

In addition to the slotted block just described, I provide preferablysmooth rotatable rolls 19. One roll is arranged on each side ot the edgeot' the sheet as is clearly indicated in Fig. 4 directly above the slotll, thus t'orming a continuation thereof. The rolls are supported uponthe rotatable shafts 90 which nay be internally cooled and are supportedand driven through the mecha msm 21. A changeable speed drive isdesirable so that the speed of rotation ot the rolls *an be controlled.The rolls 19 may either be rotated faster than the speed ot' draw if itis found that the blocks are offering too much resistance, or if theblocks have not sutticient resistance, the rolls may be rotatedrelatively slower than the speed of draw. Of course the rate of rotationof the rolls and the speed of draw can be identical if desired.

lVith the smooth rolls which may be provided with a groove 22 toaccomnodate the beaded edge 18, the sheet will be held to width while atthe same time the comparatively large knurled edge formed on the sheetheretofore will not be in evidence. The eombination of the frictionalresistance ot' the block,

as well as the heat absorption and the rotatable rolls, a decidedlyimproved edge will be formed on the sheet. The edges thus formed can betrimmed oti' and used for shelving purposes, etc., while the remainderof the sheet can be handled as heretofore.

Claims:

1. In sheet glass apparatus, means for drawing a sheet from a mass ofmolten glass, stationary means arranged at the base of the sheet at itsedges for retarding the movement ot the glass entering the sheet edges,and rotatablc means arranged above the said stationary means and closelyadjacent thei-eto.

2. In sheet glass apparatus` means for drawing a sheet from a mass ofmolten glass, slotted stationary means arranged at the base of the sheetand at its edges tor retarding movement of the glass thereto, and rollsarranged above said slotted member and closely adjacent thereto.

Tn sheet glass apparatus, means for drawing a sheet from a mass ofmolten glass, stationary slotted means arranged at the base of the sheetforretarding movement ot'glass to the border portions thereof, and apair of rolls above each of the slotted means.

4. In sheet glass apparatus, means for drawing a sheet from a mass ofmolten glass, stationary slotted means arranged at the base of the sheetat its border portions thereof, and

a pair of rotatable rolls above each slotted member adapted to engagethe edge of the sheet after it emerges from the said slot.

5. In sheet glass apparatus, means for drawing a sheet from a mass ofmolten glass, a slotted block arranged at the base of the sheet and oneat each edge thereof` a portion of each of the blocks being disposedbelow the end of the glass from which the sheet is drawn, and a pair ofrotatable rolls arranged above the slot in each block.

6. In glass drawing apparatus employing a source of molten glass fromwhich a sheet is to be drawn, means partially submerged in the source ofglass for engagement with both sides of the edge portions of the sheetbeing drawn to create a dragging action for retarding movement ot' thesheet at its border portions, and rotatable means arranged above thesaid stationary means and closely adjacent thereto. i

7. In glass drawing apparatus, employing a source of molten glass fromwhich a sheet of glass is to be drawn, means at the edges of the sheetfor holding the same to width; comprising a body portion and a pluralityot' lip portions extending therefrom and terminating below the level ofthe molten glass from which the sheet is drawn, and rotatablemeansarranged above the stationary means and closely adjacent thereto.

8. In glass drawing apparatus employiug a source of molten glass fromwhich a sheet is to be drawn, a block having spaced lip portions thereonforming a slot through which the sheet beingdrawn passes forretardingthe movement of the border portions thereof, and a pair ofrolls arranged above the slotted block for engagement with the'sheet.

9. In glass drawing apparatus employing a source of molten glassf'omwhich a sheet is to be drawn, a block having spaced lip portions thereonforming a slot through which the sheet being drawn passes forretardingthe moveent of the border portions thereof. a pair of rollsarranged above the slotted block for engagement with the sheet, andmeans for controlling the temperature of said slotted block.

10. In glass drawing apparatus employing a source ot' molten glass fromwhich a sheet is to be drawn, a block having spaced lip portions thereonforuing as lot through which the sheet beingdrawn passes tor retardingthe movement of the border portions thereot, a pair of rollsarrangedabove the slotted block for engagement with the sheet, and means forcontrolling the temperature of the slotted block and rolls.

Signed at Toledo. in the eounty of Lucas. and State of Ohio, this 3rdday of June, 1925.

FRANK FRASER.

